Fuel feed devices for internal combustion engines

ABSTRACT

In the intake pipe, a principal throttle member serves to control the flow-rate of air and is opened, against the action of a first elastic means, by an actuating member which is at the disposal of the operator and linked to the principal throttle member through a mechanical transmission. This transmission is coupled to a movable element subject to the action of the first elastic means and cooperating in such a way, with the principal throttle member, that it drives the latter in the direction of opening by mechanical contact and in the direction of closing by a second elastic means less powerful than the first. The intake pipe comprises, downstream of the principal throttle member, an auxiliary throttle member actuated in such a way, by an electromagnet which is controlled by a switch sensitive to the mutual position of the principal throttle member and of said movable element, that this auxiliary throttle member is completely opened when the principal throttle member follows faithfully, in the direction of closing, the movements of said movable element and occupies a minimal open position when the principal throttle member is retarded, in the latter direction, with respect to the movements of this movable element.

United States Patent [191 Mennesson Apr. 9, 1974 FUEL FEED DEVICES FOR INTERNAL COMBUSTION ENGINES [73] Assignee: Societe Industrielle De Brevets Et DEtudes S.I.B.E.

22 Filed: Dec. 4, 1972 21 Appl. No.: 311,560

[30] Foreign Application Priority Data Dec. 28, 1971 France 71.47140 [52] U.S. CI. 123/198 DB, 123/98, 180/82, 74/513, 123/142 I51 1 Int. Cl. F02b 77/08, 860k 27/08 [58] Field of Search 123/198 R, 198 D, 198 DB, 123/98, 108, 97 B, 102, 142; 180/82, 82.], 82.7; 74/512, 513

Primary Examine r Al Lawrence Smith Attorney, Agent, or Firm-Stevens, Davis, Miller & Mosher l 5 7 ABSTRACT In the intake pipe, a principal throttle member serves to control the flow-rate of air and is opened, against the action of a first elastic means, by an actuating member which is at the disposal of the operator and linked to the principal throttle member through a mechanical transmission. This transmission is coupled to a movable element subject to the action of the first elastic means and cooperating in such a way, with the principal throttle member, that it drives the latter in the direction of opening by mechanical contact and in the direction of closing by a second elastic means less powerful than the first. The intake pipe comprises, downstream of the principal throttle member, an auxiliary throttle member actuated in such a way, by an electromagnet which is controlled by a switch sensitive to the mutual position of the principal throttle member and of said movable element, that this auxiliary throttle member is completely opened when the principal throttle member follows faithfully, in the direction of closing, the movements of said movable element and occupies a minimal open position when the principal throttle member is retarded, in the latter direction, with respect to the movements of this movable element.

8 C ai s 2 Pt win fisyr i FUEL FEED DEVICES FOR INTERNAL COMBUSTION ENGINES The invention relates to fuel feed devices (by means of carburation or injection), for internal combustion engines comprising an intake pipe,a principal throttle member serving to control the air flow-rate in this pipe and adapted to be opened, against the action of a first elastic means, by an actuating member which is at the disposal of the operator and linked to the principal throttle member through a mechanical transmission.

Such devices have the drawback that the principal throttle member can remain stuck inuopen position, due

to friction, (which, when this throttle member is constituted by a butterfly valve fixed on a rotary axle, is exerted on this axle). It follows that, even if the operator does not apply any more pressure on the actuating member (generally a pedal) at his disposal, the engine is turning over at high speed and, where a vehicle en- 'gine is concerned, drives the vehicle with maximum power, which creates a risk of accident.

It is a particular object ofthe invention to remedy the above-mentioned drawback.

To this effect, the above-defined fuel feed device is essentially characterised by the fact that the abovementionedtransmission is coupled to a movable element subject to the action of the first elastic means and cooperating in such a way with the principal throttle member, that it drives the latter in the direction of opening by mechanical contact and in the direction of closing by a second elastic means less powerful than the first, and by the fact that the intakepipe comprises, downstream of the principal throttle member, an auxiliary throttle member actuated in such a way, by an electromagnet which is controlled by a switch sensitive to the mutual position of the principal throttle member and of said movable element, that this auxiliary throttle member, on one hand, is completely opened when the principal throttle member follows faithfully, in the direction of closing, the movements of said movable element and, on the other hand, occupies a minimal open position when the principal throttle member is retarded, in the said latter direction, with respect to the movements of this movable element.

When the principal throttle member is formed by a butterfly valve fixed on a rotary axle, it is advantageous for the said movable element to be constituted by a first lever mounted loosely on the said axle and for the abovementioned switch to comprise a first contact carried by the first lever and a second contact carried by a second lever fast to said axle, the second elastic means being mounted between the two levers. In this case, said switch can be mounted in series in the energising circuit of the electromagnet, which is arranged, when it is energised, to maintain the auxiliary throttle member open, against the action of a third elastic means. Furthermore, the electromagnet energising circuit can comprise a second switch coupled or combined with the ignition switch of the engine so that it maintains the electromagnet inactive as long as the ignition switch of the engine is not closed.

Finally, in order to facilitate the mounting of the auxiliary throttle member, it is preferable for the latter to be borne by an intermediate flange inserted between the usual part of the intake pipe carrying the principal throttle member and the rest of said pipe.

The invention will be better understood, in any case, with the aid of the complementary description which follows and of the attached drawing, which complement and drawing relate to a preferred embodiment given by way of example.

FIGS. 1 and 2 of this drawing, show in diagrammatic elevation a carburation device constructed according to the invention in the positions of its elements which correspond, respectively, to a partial load on the engine and to slow-runningwith the principal throttle member stuck in open position.

As regards the fuel feed device as a whole, it comprises, in an intake pipe 1 (where the direction of flow is shown diagrammatically by an arrow), a principal throttle member constituted by a butterfly valve 2 fixed on an axle 3. The butterfly valve 2 is arranged so as to be opened (by turning in anti-clockwise direction in the Figures) against the action of a first elastic means or spring 4, by an actuating member or pedal 5, which is at the disposal of the operator and which is linked to the butterfly valve 2 through a mechanical transmission or link rod 6.

The device also comprises means (not shown) for mixing with the air which flows in the pipe 1 and whose flow-rate is controlled by the butterfly valve 2, fuel which is introduced by suction (conventional carburation) or under pressure (injection) and whose flow-rate is substantially proportional to that of the air.

This being so, according to the invention, the link rod 6 is coupled to a movable element or lever 7 which is mounted loosely on the axle 3 and to which is hooked the spring 4. A second lever 8 is fixed on this axle. The two levers 7 and 8 carry, respectively, electrical contacts 9 and 10 which together form a switch. A second elastic means or spring 11, interposed between the levers 7 and 8, tend to maintain the contacts 9 and 10 against one another, this spring 11 being less powerful than the spring 4.

The contact 10 is connected to ground by a connection 12. The contact 9, insulated electrically with respect to the lever 7, is connected by a connection 13 to the winding 14 of an electromagnet 15, which winding is also connected to a source of voltage 16 through a switch 17 which is closed at the time of normal use of the engine. This switch 17 can be coupled or combined with the ignition switch of the engine, when the latter is of explosion type.

The electromagnet 15 also comprises a movable core 18 linked by a link rod 19 to a lever 20, which is fixed on the axle 21 of a throttle member or auxiliary butterfly valve 22 mounted in a part of the pipe 1 situated downstream of the principal butterfly valve 2. This part of the pipe 1 can advantageously be constituted by an intermediate flange 23 attached to the pipe 1. A third elastic means or spring 24, attached to the lever 20, tends to close the auxiliary butterfly valve 22, against the action of the electromagnet 15.

Finally, the device is advantageously completed by means adapted to limit the opening and closing movements of the butterfly vlaves 2 and 22. Thus, for example, a slow-running stop screw 25 can be arranged to cooperate with the lever 7.

A fuel feed device is thus obtained whose operation is as follows.

In normal running (FIG. 1), the spring 11 maintains the two levers 7 and 8 close to one another so that the contacts 9 and 10 touch each other. In consequence,

the electromagnet 15 is energised by the voltage source 16 and the movable core 18 holds the auxiliary butterfly valve 22 open, against the action of the spring 24. The flow-rate of air admitted into the engine thus only depends on the position of the principal buterfly valve 2.

If, now, for any reason, the butterfly valve 2 remains stuck in open position (FIG. 2), whilst no force is exerted on the pedal 5, the lever 7 is brought back into abutment against the screw 25 by the spring 4 which exerts a force greater than that of the spring 11. lt follows that the contacts 9 and no longer touch each other. The electromagnet is no longer energised and the spring 24 closes the auxiliary butterfly valve 22 by giving it a position such that idling or close to idling engine speeds are obtained, and this is so whatever the position of the principal throttle member 2.

A device is thus obtained which automatically and instantaneously allows the speed of the engine to be reduced, when the principal throttle member remains locked in open position and when no effort is exerted on the accelerator pedal.

In a modification, the principal throttle member and- /or the auxiliary throttle member may be constituted not by a butterfly valve but by an equivalent valve member, for example, by a slide valve adapted to slide transversely with respect to the intake pipe, in which case the movable element 7 could be arranged to slide parallel to the said slide valve.

I claim:

1. Fuel feed device for internal combustion engines, comprising in an intake pipe, a principal throttle member serving to control the flow-rate of air in this pipe and adapted to be opened, against the action of a first elastic means, by an actuating member which is at the disposal of the operator and linked to the principal throttle member through a mechanical transmission, a movable element to which said transmission is coupled and subject to the action of the first elastic means, said movable element comprising second elastic means less powerful than said first elastic means and cooperating in such a way, with the principal throttle member, that it drives the latter in the direction of opening by mechanical contact and in the direction of closing through said second elastic means, said intake pipe comprising, downstream of the principal throttle member, an auxiliary throttle member, an electromagnet arranged to actuate said auxiliary throttle member, and a switch sensitive to the mutual position of the principal throttle member and of said movable element arranged to control said electromagnet, so that this auxiliary throttle member is completely opened when the principal throttle member follows faithfully, in the direction of closing, the movements of said movable element and occupies a minimal open position when the principal throttle member is retarded, in the latter said direction, with respect to the movements of said movable element.

2. Fuel feed device according to claim 1, whose principal throttle member is formed by a butterfly valve fixed on a rotary axle, wherein said movable element is constituted by a first lever mounted loosely on said axle and said switch comprises a first contact carried by this first lever and a second contact carried by a second lever fast to said axle, the second elastic means being mounted between the two levers.

3. Fuel feed device according to claim 2, wherein said switch is mounted in series in the energising circuit of the electromagnet, which is arranged, when it is energised, to maintain the auxiliary throttle member open, against the action of a third elastic means.

4. Fuel feed device according to claim 3, for explosion engines, wherein the energising circuit of the electromagnet comprises a second switch coupled or combined with the ignition switch of the engine so that it maintains the electromagnet inactive whilst the ignition switch of the engine is not closed.

5. Fuel feed device according to claim 1, wherein the auxiliary throttle member is carried by an intermediate flange inserted between the usual part of the intake pipe carrying the principal throttle member and the rest of said pipe.

6. Fuel feed device according to claim 2, wherein the auxiliary throttle member is carried by an intermediate flange inserted between the usual part of the intake pipe carrying the principal throttle member and the rest of said pipe.

7. Fuel feed device according to claim 3, wherein the auxiliary throttle member is carried by an intermediate flange inserted between the usual part of the intake pipe carrying the principal throttle member and the rest of said pipe.

8. Fuel feed device according to claim 4, wherein the auxiliary throttle member is carried by an intermediate flange inserted between the usual part of the intake pipe carrying the principal throttle member and the rest of said pipe. 

1. Fuel feed device for internal combustion engines, comprising in an intake pipe, a principal throttle member serving to control the flow-rate of air in this pipe and adapted to be opened, against the action of a first elastic means, by an actuating member which is at the disposal of the operator and linked to the principal throttle member through a mechanical transmission, a movable element to which said transmission is coupled and subject to the action of the first elastic means, said movable element comprising second elastic means less powerful than said first elastic means and cooperating in such a way, with the principal throttle member, that it drives the latter in the direction of opening by mechanical contact and in the direction of closing through said second elastic means, said intake pipe comprising, downstream of the principal throttle member, an auxiliary throttle member, an electromagnet arranged to actuate said auxiliary throttle member, and a switch sensitive to the mutual position of the principal throttle member and of said movable element arranged to control said electromagnet, so that this auxiliary throttle member is completely opened when the principal throttle member follows faithfully, in the direction of closing, the movements of said movable element and occupies a minimal open position when the principal throttle member is retarded, in the latter said direction, with respect to the movements of said movable element.
 2. Fuel feed device according to claim 1, whose principal throttle member is formed by a butterfly valve fixed on a rotary axle, wherein said movable element is constituted by a first lever mounted loosely on said axle and said switch comprises a first contact carried by this first lever and a second contact carried by a second lever fast to said axle, the second elastic means being mounted between the two levers.
 3. Fuel feed device according to claim 2, wherein said switch is mounted in series in the energising circuit of the electromagnet, which is arranged, when it is energised, to maintain the auxiliary throttle member open, against the action of a third elastic means.
 4. Fuel feed device according to claim 3, for explosion engines, wherein the energising circuit of the electromagnet comprises a second switch coupled or combined with the ignition switch of the engine so that it maintains the electromagnet inactive whilst the ignition switch of the engine is not closed.
 5. Fuel feed device according to claim 1, wherein the auxiliary throttle member is carried by an intermediate flange inserted between the usual part of the intake pipe carrying the principal throttle member and the rest of said pipe.
 6. Fuel feed device according to claim 2, wherein the auxiliary throttle member is carried by an intermediate flange inserted between the usual part of the intake pipe carrying the principal throttle member and the rest of said pipe.
 7. Fuel feed device according to claim 3, wherein the auxiliary throttle member is carried by an intermediate flange inserted between the usual part of the intake pipe carrying the principal throttle member and the rest of said pipe.
 8. Fuel feed device according to claim 4, wherein the auxiliary throttle member is carried by an intermediate flange inserted between the usual part of the intake pipe carrying the principal throttle member and the rest of said pipe. 